Reciprocatory fluid pump

ABSTRACT

A reciprocatory fluid pump includes an armature assembly reciprocatably mounted in a housing and two leaf springs that are connected in parallel at two sides between the armature assembly and the base of the housing to constrain the reciprocations of the armature assembly to transverse displacements, enhancing the pumping efficiency and preventing friction during the reciprocating motion of the ferromagnetic member of the armature assembly, and therefore the reciprocatory fluid pump eliminates energy loss and generation of noises.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to fluid pumps and more particularly, to a reciprocatory fluid pump, which uses two leaf springs to constrain the reciprocations of the armature assembly to transverse displacements, preventing friction and enhancing pumping performance and eliminating friction loss.

2. Description of the Related Art

Many reciprocatory fluid pumps have been developed for low-pressure applications. These known reciprocatory fluid pumps generally include two pumping members, e.g., diaphragms, at its opposite ends, driven by two electromagnets. Other designs have been proposed including a single electromagnet driving two pumping members, e.g. diaphragms. Examples of such prior art pumps are described in U.S. Pat. Nos. 4,859,152 and 4,154,559. According to these known reciprocatory fluid pumps, the diaphragms are frequently deformed to produce a suction force for moving a fluid, in consequence the diaphragms wear quickly with use, showing the work life of the pump. Further, these known reciprocatory fluid pumps generate considerable sound and vibration and are less stable during operation. There are known rotary fluid pumps commonly use a motor to move a pumping member. During operation, the motor consumes about 50˜80 W. Therefore, a cooling fan is necessary to lower the temperature of the pump. Because of a cooling fan is necessary, a rotary fluid pump cannot be used in an enclosed space and tends to suck in external bodies during operation.

Further, U.S.A. publication number US2008/0050251A1 discloses a reciprocatory fluid pump. According to this design, as shown in FIGS. 8 and 9, the reciprocatory fluid pump comprises a housing A, an electromagnet B mounted in the housing A at a top side and defining therebelow an air gap B1, an armature assembly C, which is reciprocatably mounted to the housing A by a pair of spaced leaf springs D extending parallel to each other and fixed at their opposite ends to the armature assembly C and the housing A, respectively, and a diaphragm E connected to one side of the armature assembly C. The diaphragm E is driven by the armature assembly C to reciprocate, thereby discharging a fluid.

According to the aforesaid prior art design, the leaf springs D are flat sheet members having a big surface area and an anti-deformation capacity. However, during reciprocation of the armature assembly C subject to the operation of the electromagnet B, great magnetic attraction and repellant forces are necessary to cause the leaf springs D to deform as desired. In consequence, the electromagnet B consumes much power and cannot be small-sized.

Further, according to the aforesaid prior art design, the diaphragm E is alternatively formed in two directions to produce a pumping action and the border of the diaphragm E is movably connected to a valve assembly F, therefore the border edge of the diaphragm E wears quickly with use due to friction and elastic fatigue and deformation damage tend to occur in the diaphragm E after a long use, thereby shortening the work life of the pump.

SUMMARY OF THE INVENTION

The present invention has been accomplished under the circumstances in view. It is one object of the present invention to provide a reciprocatory fluid pump, which enhances the pumping performance and prevents friction during the reciprocating motion of the armature assembly, thereby eliminating energy loss and generation of noises.

To achieve this and other objects of the present invention, a reciprocatory fluid pump comprises a housing, an electromagnet fixedly mounted inside the housing and defining an air gap, an armature assembly inserted through the air gap and magnetically coupled to the electromagnet for making a reciprocating motion when the electromagnet is energized, a pumping member connected to the armature assembly movable alternatively back and forth by the armature assembly, a valve assembly matching the pumping member, and two leaf springs connected in parallel at two sides between the armature assembly and the base of the housing to constrain the reciprocations of the armature assembly to transverse displacements, enhancing the pumping efficiency and preventing friction during the reciprocating motion of the ferromagnetic member of the armature assembly. Because no friction is produced during a reciprocating motion of the ferromagnetic member of the armature assembly, the invention avoids energy loss and does not cause noises during operation. Because of high working efficiency, power consumption (consuming power is about 15 W) and generation of heat energy are greatly reduced. Further, the reciprocatory fluid pump can be used in an enclosed space, avoiding suction of external bodies into the inside of the pumping chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a reciprocatory fluid pump in accordance with the present invention.

FIG. 2 corresponds to FIG. 1 when viewed from another angle.

FIG. 3 is a sectional side view of the reciprocatory fluid pump in accordance with the present invention.

FIG. 4 is an elevational view of one leaf spring according to the present invention.

FIG. 5 is a schematic sectional view showing the operation of the reciprocatory fluid pump in accordance with the present invention (I).

FIG. 6 is a schematic sectional view showing the operation of the reciprocatory fluid pump in accordance with the present invention (II).

FIG. 7 is a perspective view of an alternate form of the reciprocatory fluid pump in accordance with the present invention.

FIG. 8 is a sectional view of a reciprocatory fluid pump according to US2008/0050251A1.

FIG. 9 illustrates the structure of the leaf spring used in the reciprocatory fluid pump according to U.S.A. publication number US2008/0050251A1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 1-3, a reciprocatory fluid pump in accordance with the present invention is shown comprising a housing 10, an electromagnet 20, an armature assembly 30, a pumping member 40 and a valve assembly 50.

The housing 10 has a base 11 and a sidewall 12 upwardly extended from the border of the base 11.

The electromagnet 20 comprises a body 21, at least one winding 24 mounted in the body 21 and a plurality of tie rods 22 inserted through the body 21 to affix the body 21 to the upper part of the sidewall 12 of the housing 10 in such a manner that an air gap 23 is defined in the housing 10 beneath the body 21.

The armature assembly 30 is mounted in the air gap 23 at the bottom side and magnetically coupled to the electromagnet 20. The armature assembly 30 comprises a ferromagnetic member 31, two permanent magnets 32 fixedly mounted on the top surface of the ferromagnetic member 31 and two leaf springs 33 arranged in parallel at two opposite sides relative to the ferromagnetic member 31. The leaf springs 33 are shaped like a rectangular open frame, each comprising a first base portion 331, a second base portion 333 and two arms 332 connected in parallel between the two distal ends of the first base portion 331 and the two distal ends of the second base portion 333. Fastening members 34 are respectively inserted through the center area of the first base portion 331 and the center area of the second base portion 333 of each of the two leaf springs 33 to affix the two leaf springs 33 to two opposite sides of the ferromagnetic member 31 and two opposite sides of the base 11 of the housing 10.

The pumping member 40 is provided at one side of the armature assembly 30, comprising a piston 42, a link 41 connected between the piston 42 and one side of the ferromagnetic member 31 and a piston ring 421 mounted on the periphery of the piston 42. The piston 42 is made of a flexible material capable of absorbing micro elevational displacement during the reciprocating motion of the ferromagnetic member 31 so that the piston ring 421 can be constantly kept in contact with the inside wall of the piston chamber 511 in the valve assembly 50.

The valve assembly 50 comprises a valve block 51 connected to one side of the body 10 and defining therein a piston chamber 511, which receives the piston 42 in such a manner that the piston ring 421 is kept in contact with the peripheral wall of the piston chamber 511 in a watertight manner and movable with the piston 42 relative to the piston chamber 511, and a pumping chamber 52 connected to one side of the valve block 51 opposite to the body 10. The pumping chamber 52 has connected thereto an inlet pipe 521 and an outlet pipe 522.

Referring to FIGS. 4-6, during operation of the reciprocatory fluid pump, alternating current is applied to electromagnet 20, the magnetic attraction and repellant forces applied by the electromagnet 20 to the two permanent magnets 32 reciprocate the ferromagnetic member 31 at the frequency of the power supplied to the electromagnet 20. During the reciprocating motion of the ferromagnetic member 31, the leaf springs 33 which, because of the parallelogram arrangement defined by the two leaf springs 33 with ferromagnetic member 31 on one side, and with base 11 on the opposite, constrain the reciprocations to transverse displacements, and at the same time the arms 332 of the leaf springs 33 are curved alternatively leftwards and rightwards, causing transverse displacements of the first base portions 331 of the two leaf springs 33 with the ferromagnetic member 31. The reciprocations of the ferromagnetic member 31 are transferred by the link 41 to the piston 42, causing the piston 52 to reciprocate in the piston chamber 511. The reciprocations of the piston ring 421 change the volume within piston chamber 511, thereby sucking fluid into the pumping chamber 52 via the inlet pipe 521, and pumping fluid out of the pumping chamber 52 via the outlet pipe 522.

Referring to FIG. 7, the housing 10 is mounted inside a frame shell 70 and supported on spring members 60. The spring members 60 are arranged around the four sides of the housing 10, each comprising a coil body 61, a first connection end portion 62 extended from one end of the coil body 61 and a second connection end portion 63 extended from the other end of the coil body 61. The first connection end portion 62 of each spring member 60 is connected to the housing 10. The second connection end portion 63 of each spring member 60 is connected to the bottom side of the frame shell 70. By means of the spring members 60, the housing 10 is suspending inside the frame shell 70. Thus, during the reciprocating motion of the ferromagnetic member 31, the coil bodies 61 of the spring members 60 absorb shocks, thereby eliminating noises.

In conclusion, the invention provides a reciprocatory fluid pump, which has the following features:

1. The invention utilizes two parallel leaf springs 33 to constraint the reciprocations of the ferromagnetic member 31 to transverse displacements, enhancing the pumping efficiency of the pumping member.

2. The leaf springs 33 are shaped like a rectangular open frame. During operation of the ferromagnetic member 31 to reciprocate the leaf springs 33 transversely, the arms 332 of the leaf springs 33 are curved alternatively leftwards and rightwards, constraining the reciprocations of the ferromagnetic member 31 to transverse displacements. Further, the two arms 332 of each leaf spring 33 are respectively downwardly extended from the two distal ends of the first base portion 331 of the respective leaf spring 33. The limited surface area of the arms 332 enables the arms 332 to be easily curved by the magnetic attraction and repellant forces applied by the electromagnet 20 to the two permanent magnets 32, i.e., small magnetic attraction and repellant forces are enough to cause the arms 332 of the leaf springs 33 to curve, and therefore the electromagnet 20 is optimized for small size.

3. Fastening members 34 are respectively inserted through the center areas of the first base portion 331 and second base portion 333 of each of the two leaf springs 33 to affix the two leaf springs 33 to two opposite sides of the ferromagnetic member 31 and two opposite sides of the base 11 of the housing 10, the limited fixation area of the leaf springs 33 does not affect elastically deformable performance of the leaf springs 33, avoiding the problem of elastic fatigue.

4. The invention improves the performance of the pump and enables the electromagnet 20 to be small-sized. Therefore, the invention effectively reduces power consumption and generation of heat energy during operation, and can be operated in an enclosed space, preventing suction of external bodies into the pumping chamber.

5. Curving of the arms 332 of the leaf springs 33 to constrain the reciprocations of the ferromagnetic member 31 to transverse displacements does not cause friction during the reciprocating motion of the ferromagnetic member 31, avoiding energy loss due to friction and eliminating noises.

6. Spring members 60 are used to absorb shocks during the reciprocating motion of the ferromagnetic member 31, eliminating generation of noises.

7. The piston 42 is mounted with a piston ring 421 that has its periphery constantly kept in close contact with the peripheral wall of the piston chamber 511 such that the reciprocations of the piston ring 421 change the volume within piston chamber 511. During the reciprocating motion of the piston 42 in the piston chamber 511, the piston ring 421 simply causes a small amount of deformation, prolonging the work life of the piston 42.

Although a particular embodiment of the invention has been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims. 

1. A reciprocatory fluid pump, comprising: a housing has a base and a sidewall upwardly extended from the border of the base; an electromagnet fixedly mounted in said housing at a top side and defining an air gap therebelow; and an armature assembly mounted in a bottom side in said air gap and magnetically coupled to said electromagnet, said armature assembly comprising a ferromagnetic member, two permanent magnets fixedly mounted on a top surface of said ferromagnetic member and two leaf springs shaped like a rectangular open frame and connected in parallel between said ferromagnetic member and the base of said housing at two opposite sides.
 2. The reciprocatory fluid pump as claimed in claim 1, further comprising a pumping member disposed at one side of said housing and a valve assembly working with said pumping member, said pumping member being connected to said armature assembly and controllable by said armature assembly to reciprocate.
 3. The reciprocatory fluid pump as claimed in claim 1, further comprising a pumping member disposed at one side of said housing and a valve assembly working with said pumping member, said valve assembly defining therein a piston chamber, said pumping member comprising a piston, a link connected between said armature assembly and said piston and a piston ring mounted on the periphery of said piston and kept in close contact with the peripheral wall of said piston chamber and movable with said piston in said piston chamber.
 4. The reciprocatory fluid pump as claimed in claim 1, wherein said piston is made of an elastic material.
 5. The reciprocatory fluid pump as claimed in claim 1, wherein each said leaf spring comprising a first base portion, said first base portion having a center area affixed to said ferromagnetic member with a fastening member, a second base portion and two arms connected in parallel between two distal ends of said first base portion and two distal ends of said second base portion.
 6. The reciprocatory fluid pump as claimed in claim 1, further comprising a frame shell adapted to accommodate said housing, and a plurality of spring members connected between said frame shell and said housing to suspend said housing inside said frame shell.
 7. The reciprocatory fluid pump as claimed in claim 1, wherein said spring members each comprise a coil body, a first connection end portion extended from one end of said coil body and connected to said housing and a second connection end portion extended from an opposite end of said coil body and connected to said frame shell. 